I am happy to see that article. There are people who love tankless, and more power to them. Sometimes, you are made to feel like a heretic or a luddite for opposing tankless.
I have always maintained that the ONLY advantage possible with a tankless is that MULTIPLE folks can take sequential showers. Or you can fill a large tub. These applications are where the 70% rule on tank heaters catches up with you. But for most homes, forget it . The payback time is LONG.
I can remember some places I stayed at in Hong Kong had tankless heaters...it was literally IN the shower....hanging right there on the wall. It put out HOT water, right away. I suspect it did not have a lot of the safeties that today's units do, so the water came on hot and stayed hot. It was great! I imagine that the space savings in small apartments, and saving on running all that hot water pipe everywhere....was the reason for using them. I don't remember, but I don't think there was anything but cold in the sinks.
I agree with CU's usage numbers. I keep spreadsheets of water usage in my condo comlex ( we have usage issues!). Over a couple of years data, our usage runs about 165 gallons per day, per unit. Now the units are a mix of 1 and 2 BR, one to 4 persons per unit ( occasionally 7 illegal aliens in one unit!). 2BR units have 2 baths, all units have DW and WM. So the data is blended. This number does not include landscape, which is on a separate meter.